Color photography.



'F. E. WES.

COLOR PHOTOGRAPHY,

APPLICATION men FEB, 20. 1912.

Patented Sept. 10, 1918.

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FREDE R'IC EUGENE IVE S, OF PHILADELPHIA, PENNSYLVANIA.

COLOR PHOTOGRAPHY.

Specification ofLters Patent. Patented Sept. It), I918.

Application filed February 20, 1917. Serial No. 149,743.

' To all who m'z't may concern: s

Philadelphia, in the and State of Pennsylvania, have invented Be it known that I, FREDERIO E. Ivns, a citizen of the United States, residing at countyof Philadelphia certain new and. useful Improvements in ColorPhotography, of'which the following images.

is a specification,reference being had therein, to the accompanying drawing.

This invention relates to the art of color photography, and has more particularly to do with the processor steps involved in the making of a multi-color photograph or picture compounded of blended monocolor In its complete aspect the present process may be said to commence-with a set of coIor selectionv negatives, whether of thee two-color or three-color system, or other system, whichv negatives are producible by well-known methods; and'the present invention provides. a novel and advantageous mode of proceeding from such negatlves to secure the multi-color positives or pictures. In one aspect the present invention may be said to be directed more particularly to the subject of motion pictures in color, a branch of the art of color photography, and in, which,on account of the minute size of thd images, it has been found diflicult to accurat-ely secure or insure exact registration .of the component images. The present invention by overcoming such difiiculties prevents the incidental formation of fringes of color in the making and exhibiting of color motion pictures. 4 1

I will hereinafter for convenience de scribe the'invention as applied to the'twocolor system, wherein red and green, respectively, may be considered as the selected primary colors, and blue-green and red, respectlvely, the, corresponding secondary or complementary colors; Also, while the invention is applicable to many systems wherein the monochrome components of the positive image are produced successively, the later one being produced directly upon and in registry, so as toblend, with the-earlier one, I shall for convenience of description assume the process described in my prior Patent No. 1,170,5 1 of February 8, 1916,

and will point out owthe present invention should be practised as an improvement thereon. p In said prior Patent 1,170,540, after obtaining the negatives representing the selected primaries, and which may bekrespec- This I preferably present invention.

v The objects tively referred negative and the greenrepresenting negative, I proceeded by first making a mono- 'tive from one of the negatives.

chrome pos1 Specifically, I produced a blue-green positive directly ti've, this colored gelatin film'on ,a suitable support. then used thegreen-representing negative or a diapositive therefrom to print directly upon the blue-green monochrome print a red image in registry with the blue-green image.

did by bichromate-sensitizing of the gelatin film containing the blue-green image andthen exposing beneath a diapositive from the green-representing negative, and thereafter dyeing the exposed colloid by suitable red dye which is selectively imbibed, forming an image blending with th'e'blue-green image and yielding the desired multi-color print. It will be understood that the negatives and the green-representing diapositive referred to are the usual black, or rather, black and clear, negatives or diapositives' To avoid confuto as the red-representing from the red-representing negapositive being carried in a sion I shall throughout this specification use the word color or colored in'a sense distinguished from black or clear.

In practising the process of Patent 1,170,540, I have repeatedly difiiculty which I have now overcome by the This difficulty was to secure accurate registration of the black greenrepresenting diapositive over the previously formed blue-green monochrome positive. Practically, speaking, visual registration is necessary, at least in the first instance, and I have found that the most minute visual examination, however carefully made, has not availed to insure exact "registration.

\ The difiiculty is enhanced in the case of cine matographic films where the details of the pictures. are substantially microscopic, and

where, moreover, the slightest inaccuracy in encountered aregistration is immensely magnified in pro-v jecting the picture upon the screen. In accuracy in registry means that one or other of the color images,the blue-green or the red, will overlap 'atvarious points, thus producing bright color fringes in the projected picture, which is extremely ObJGCtlOIlflblQ.

various defects generally to overcome the above mentioned, and particularly to overcome the difiicult in exact registration in the printing or b ending of a second monoof the present invention are I ticularly consists in the process of making a blended picture after having secured a preformed color -print or positive by photographicallyprinting a differently colored.

image 1n registry upon, so" as to blend with, the preformed color print by efiecting a photographic exposure through a diaposinegative, and Fig. 3 a diapositive from the' tive, or in some cases a negative, which, contrary to the usual black and clear diapositive or negative, is of a color which effectively contrasts with that of the preformed print, so that the eye is easily enabled to effect exact registration before exposing to light to print in the second image. Thereby is overcome the defect in the prior patent that the black and'white diapositiveafi'ords insufiicient contrast with the preformed monochrome image during the step of registry. More specifically, I prefer, after securing the first color image, to use for the printmg of the succeeding one a diapositive of the complementary color, so that during the ste of registry the observer practically has be ore him the final multi-color or blended image. Specifically, after securing the blue-green positive in gelatin and resensitizing, I employ a red diapositive secured from the green-representing negative, and with this red diapositive registration above the blue-green image is easily and satisfactorily made prior to. the actual exposure and subsequent selective dyeingof the gelatin.

In order to afford a full-and complete dis closure of the present invention, and the mode of practising it, I will set forth step by step one practicable mode of procedure and details; and any detailsnot herein fully set forth may be ascertained by reference to said prior Patent 1,17 0,540, or will be well understood by those skilled in the art; but,

since many matters of detail, order'of procedure, and other features may' be obviously variously modified, I do not intend to limit my invention to the described features ex-- Figure. 1 in side elevation indicates 'aredselection negative, Fig. 2 a green-selectior green-selection negative. Fig. 4 indicates the ste of printing a blue-green positive on the re -selection, Fig. 5 the step of printing aeraee'z a red image from the Fig. 3 diapositive in registry upon the blue-green image, and Fig. 6 on an enlarged scale shows the nature of the resulting print. .Fig. 7 shows a modification.

Commencing the description of the present invention at that point where the color selectionnegatives have been obtained, and assuming that one of these represents red and the other green, these being the selected primaries, the subsequent procedure may be in detail as follows:

Before producing a blue-green positive from the red selection negative 10, it will be convenient to first secure the red diapositive from the green-representing negative 11 for the purpose of using such diapositive in exposing and printing the second of the two monochrome images to be blended.

From the black negative 11, which represents green, I print ablaok diapositive 12, which may be done in a well-known manher, for example, by merely exposingasilver haloid sensitive plate or film beneath the negative and developing in the usual way. I next convert the black diapositive into a red diapositive, and the procedure for this may be as follows:

I first soak the diapositive over night in a copper toning solution made up of the following solutions, which can be kept in stock:

I Solwtton- A. Potassium ferricyanid 50 grains Potassium citrate 240 grains vIlvater a V 20 ounces Sohatz'on B. Copper sulfate 60 grains Potassium citrate '240 grams Water Q. 20 ounces A mixture of equal parts of solutions A and B gives the desired toning solution, "and, when the diapositive has been soaked for the requisite time, it will be found to have been converted into a copper red colored image. This image is' somewhat degraded by the presence of silver ferricyanid, and I, therefore, prefer to dissolve out this silver salt by the use of sodium thiosulfate (u yp w) I prefer that the diapositive 12 should be of a deeper and brighter red than the cop-. per red so produced, in order to give a more emphatic contrast when registering with the 120 blue-green image, and this result may be accomplished as follows? The copper red diapositive may then be soaked in an aqueous solution of fuchsm dye containing. a small quantity of acetic acid. 125.,

names? negative 10- will first be utilized to secure a blue-green positive image, which may be done on the silver conversion system mentioned in Patent 1,170,540, or by any other convenient system. This step is indicated in Fig. 4, in which beneaththe negative 10 is seen the print member 13, comprising the sensitive layer 14 overthe carrier or glass'15.

first formed image andthe print1ng mem- Having the blue-green positive image, the second'image may be produced and blended in difl'erent ways. One well-known pro= cedure would be to first coat the blue-green image with aprotective coating of varnish 16, as indicated in Fig. 7, and apply over that a sensitive layer '17 before proceeding to expose and print for the red image. The

- present invention is independent of the particular location or relative arrangement'of the blended images, having to do with the roblem of securing registration between the her used for printing the second lmage, which latter I may sometimes indeed locate on the rear or reverse side ofthe transparexit carrier, as has been heretofore-proposed.

Or I may proceed as in said Patent 1,170,540,

wherein the blue-green image is contained in 'a gelatin layer 14, see Fig. 5, which may now be sensitized with potassium bichromate. This resensitized monochrome may now be exposed beneath the green-representing red-colored diapositive 12; This, as previously explained, is easil ionic acid, known as fast red or similar dye.

.By this procedurethe redimage' will be created by selective absorptio t and will be found to be accurately regi ered with the blue green image, and therefore properly blended, so that, when magnified by projecttion on a motion picture screen, the objectionable color elinfinated'. I

In enlarged cross-section the final picture may be somewhat as indicated in Fig.- 6, wherein above the transparent carrier 15 the layer 14 of colloid is shown as having embodied in it the blue-green image 18 and the subsequently formed red image 19, the lower colored re d to silver iodid and accurately. performed by reason of t e color contrast. the blueand the same have fringes will be substantially part of the colloid layer being clear, as

ima e. v

, The particular colors instances,'and they may ably altered according to the system of primaries and secondaries that may be selected.

In the particular two-color system referred mentioned are only to, the red image may be of various shades of red as circumstances may dictate, and the blue-green image may vary from blue to green, and may, therefore, be referred to as a blue-to-green image.

Other methods than the one be employed for converting a .b

iven may this process. For example, the method of the Traube Patent 1,093,503 of August 14, 1914, wherein the silver image is converted and subsequently dyed with an alkali dyewhich is mordanted by s lver iodid; and a silver image converted to sllver ferricyanid will dye selectively with alkall dyesin the same manner. dye image is preferable for' the-object of my invention because of its intrinsic color an superior opacity to actinic light and the eater permanency in combination with the; copper mordant. This image, and the process of producmgnt have a wider utility than as above descr1 ed been divided out from the claims hereof and were made thesub ject of interference between my divisional application No. 195,508, [filed October 9, 1917, and application of J. ll. Crabtree No.

144,557, filed Januar 25, 1917, under which the original black negative may be be reversed or suit-V ack silver. image to a colored image, as requ red for the use of a dye like eosin, which is mordanted by the chromium;

the

dso positive image prlnting under a negative The copper and tojlight of alkali dyes respective applicationscross-licenses to the owners thereof have been granted.

What I claim as my'invention is:

1. In the art of color photography the process of making a multicolor photograph from a set of color selection negatives which represent the respective selected primary colors, said process consisting in printing from one, negative a monochrome positive of a secondary color corresponding to the first primary, producing from another negative a colored printing member contrasting in color with such positive, and then print- ,ing from said printing member in registry 7 color with such blue-to-green positive, and J y from one negative a monochrome positiveof a secondary color corresponding to the first primary, producing from another negative a. colored diapositive contrasting in .color with such positive and then printing from said diapositive in registry with said positive a color image of a secondary color corresponding to the second primary.

3. In the art of color photography the process of making a multicolor photograph from a set of color selection negatives which represent the respective primary colors red and green, said process consisting in printing from the red-representing negative a monochrone positive of a blue-to-green color, producing from the green-representing negative a colored diapositive contrasting in then printing from said colored diapositive in registry with said positive a red image.

4. In the art of color photography the process of making a multicolor photograph from a set of color selection negatives which represent the respective primary colors red and green, said process consisting in printing from the red-representing negative, a monochrome positive of a blue-to-green color, producing from the green-represent, ing negative a red diapositive, and then printing from said red diapositive in regis-' try with said positive a red image. f

5 In the art of color photography the process of making a multicolor photograph from a set of color selection negatives which represent the respective primary colors red with the preformed print.

. nere eer and green, said process consisting in printing from the red-representing negative, a monochrome positive of a blue-to-g'reen color and thereafter resensitizing such colored positive, producing from the. greenrepresenting negative a, color diapositive contrasting in color with such blue to-green positive, and 'then printing from said diapositive in registry with said positive a red image.

6.111 the art of color photography the process of making a multicolor-photograph from a set of color selection negatives which represent the respective primary colors'red v diapositive in registry with said positive, a

red image.

7. In the art of color-photography the process of making a multicolor photograph from a set of color-selection negatives, consisting in producing a color image by printing from one of the negatives, producing from another of the negatives a diapositive of a color contrasting with the color of the first mentioned image, and subsequentlyproducing in registry with the first image a second image of a difi'erent color by printing from said color diapositive.

8; The process of making a multicolored photograph consisting in photographically printing a color image in registry with a preformed color print by exposure througha diapositive havinga color that contrasts In testimonywhereof, l have aflixed my signature hereto.

FREDERIC EUGENE rvns. 

